Manufacture of pipes and the like from sheet metal



March 8, 1938. w. R. HUME 2,110,378

MANUFACTURE OF PIPES AND THE LIKE FROM SHEET METAL Filed May 26, 1934 5 Sheets-Sheet l W. R. HUME March 8, 1938.

MANUFACTURE OF PIPES AND THE LIKE FROM SHEET METAL s shets-sheet 2 Filed May 26, 1934 March s', 193s. w R, UME 2,110,378

MANUFACTURE OF PIPES AND THE LIKE FROM SHEET METAL Filed May 26, 1954 5 Sheets-Sheet 3 Patented Mar. 8, 1938 MANUFACTURE OF PIPES ANVI?) THE LIKE FROM SHEET METAL Waiter Reginald Hume, Melbourne, victoria, Australia, assignor to Hume Steel Limited, Melbourne, Victoria, Australia Application May 26, 1934, Serial No.- 727,812

In Australia June 15, 1933 6 Claims.

This invention relates to the manufacture of lsheet metal pipes and like hollow bodies wherein flat metal plate is caused to travel lengthwise between successive sets of shaping rollers which progressively bend the plate from its longitudinal edges towards its center so that the plate converges from the flat at one end into tubular form at the other end.

In` prior proposals of this kind, some or all of the sets of shaping rollers consist of an upper roller and a lower roller, both rotatable about horizontal axes and extending across the longitudinal center line of the plate, the respective rollers having complementary convex-concave peripheral faces which engage the upper and lower surfaces of the plate. Owing to the rollers extending across the center line of the plate as aforesaid, the longitudinally extending central zone of the plate is, from the time the plate enters 'between the first rollers until it assumes or approaches the desired tubular condition, continuously subject to bending or to pressure by the various pairs of rollers. This bending or pressure, which is additional to the bending or pressure that is actually necessary for imparting the desired finished curvature to the plate, considerably increases friction between the plate and rollers as well as Wear on the rollers and may result in the central longitudinal zone of the plate, while fiat, being compressed to an extent sufficient to disaffect the subsequent bending of the central zone or causevthe finished pipe to lose its true circular section or cylindrical shape.

The present invention provides an improved like hollow bodies according to which a plate while moving lengthwise is subjected at each side of its longitudinal center line, but not at or across such center line, to pressure between sets of shaping rollers whereby portions of the plate at opposite sides of the 'center line are progressively bent towards each other in arcuate form until the longitudinal edges thereof meet, the radii of all of the bends being the same as the radius of the pipe to be formed, so that subsequent bending actions merely extend or continue the curvature of previously curved portions without subjecting said portions to further bending or pressing actions, while a flat longitudinally extending central portion of the plate of generally isosceles triangular shape which gradually diminishes in area as bending operations proceed remains unsubjected to pressure or bending until the apex or leadingend thereof is adjacent theflnal set of rollers. The fact that the longitudinal 52. method of manufacturing sheet meta-1 pipes and,

central zone of the plate remains fiat and unsubjected to pressure as aforesaid tends to keep the work perfectly straight during bending operav tions so that a substantially perfectly straight tube results. c

The invention'also provides apparatus for carrying the method intoeiect and comprising sets of shaping rollers between which the plate is caused to pass, arranged 'at intervals in the direction of travel of the plate, some of the rollers of each set being located at one side and the other rollers at the opposite side of the longitudinal center line ofthe plate, each set of rollers comprising two lower or outside rollers adapted to rotate about vertical axes and havingv peripheries of concave curvature conforming, to the external curvature of the pipe to be formed, and two cooperating upper or inside rollers adapted. to rotate about a transverse axis and having peripheries of convex curvature conforming to th'e internal curvature of th'e pipe to be formed,` each succeeding set of rollers being disposed nearer to the longitudinal center line of the plate than the preceding set so that the plate is progressively bent from its longitudinalV edges towards the center thereof into tubular form.

According to a preferred mode of carrying out the method, a plate in a substantially flat condition is fed to and lcaused totra'vel longitudinally between sets of shaping rollers arranged l at intervals in the direction of travel of the plate, some ofthe rollers of each set being located at one side, and the kother rollers atA the opposite side, of the longitudinal centre line of the plate. The rst group or set of shaping rollers'act upon the longitudinal edgeportions of the plate to bend these portions arcuately in conformity with the curvature of the finished pipe or like body.

Each succeeding .set of rollers is disposed nearer to the longitudinal centre line of the plate than the preceding series of rollers and act upon the platel in a similar manner so that its longitudinal edge portions are gradually or progressively bent into senil-circular form and their longitudinal edges abutted ready for welding together. The plate isfed forwardly by the shaping rollers.

vThe vinvention permits of the economic production of pipes which are practically perfectly straight and cylindrical and of relatively great length devoid of circumferential joints.

' The invention also involves apparatus for carrying out the' manufacture of pipes by the'improved method.

Referring to the drawings which form part of this specification- Figure 1 is a side elevation of a machineaccording to one embodiment of the invention'.

Figure2illaplanofF'lgure1.V F'igure 3 is an end elevation looking onvr the left hand end of Figure 1. n

. Figure 4 isa perspective view illustrating the manner of bending the plate into tubularform.

Figure 5 is a fragmentary end view on an enlarged scale of one of a set of shaping rollers, and associated parts of the machine.

Figure 6 is a part sectional view taken on line VI-VI'of Figure 5. l Y

Figure 7 is a fragmentary end view of .a further set ot shaping rollers and aociated parts.` 1

r Flgure 8 is aside elevation of the nal twoscts of shaping rollers and associated parts. p Figure 9 is an end view oi the sets of rollers and associated parts seen in the left hand portion side of Figure 8. f

Figure 10 is vie'w` of thennal set'of ,rollers-and seen in the right handportionoiFlg'ure. Y 1l is a detail view partlyin 'section showings bar and a backing member whichfextend within theshaped metal sheet adiacent the iinal shaping rollers in order toV assist the welding. ot abutted longitudinal edges of the Figure 12 is anv end view looking on the right hand end of Figure 1l.

' 13 is an' enlarged plan view of a lower` portionoi the `backing' member seen in Figures 1iA and 12 showing arrangements for the water 14 is a vertical cross section taken through the 'centre'of the backing member.

- morder tumore readily explain the method.

reference is made to Figure 4 which depicts a plate 2 in an intermediate stage of the bending vshape having the trailing edge 2a as its base and its sides, indicated by the references 2d, de-

iinedwby lines from which the longitudinal edge portions 2b commence to curve upwardly from theV iiat'portion by the action of the successive sets of rollers. ,The approximately triangular ,iiat'portion will gradually diminish in area asthe bending operations proceed and will disappear just prior to the entire plate arriving at a tubular condition.

' Referringnow 'more particularly to Figures 1, e '2 and 3. the'apparatus is shown as including reight sets of'shaping rollers,l the various sets bejing denoted `generally in Figure 1 by the referf ence characters A, B,'C,`D, E, F, G, H. The plate V2 to be in the direction from the A set of rollers to the "Hset so that it is 'progressively byeach` succeeding set ythesameastheraciiusoilthepipetolle substantially identical with those of seta be gradually( with the longitudinal centre lille of the plate 2.

'Ihe periphery of each horizontally rotating out side roller I is of concave curvature and of approximately quarter-circular profile, conforming Vupon a transverse spindle 1. ille periphery of each roller l is of convex curvature conforming to the internal curvature oi the pipe Vto be" formed. Thus. Aas the plate 2 is entered and passed-between the cooperating pairs of rollers 2. i. the longitudinal edge portions of the leading end ofthe plate are initially bent into the desiredcurvedform, theradius of thebends being iormed while'theV centralportion of the pla 'Ihe rollers of sets are indicated by like numerals. The rollers 'eachfsuccessive set are, however. arranged closer to the longitudinal centre line lof 'the apparatus as will be seen in Figure 2 so that'thefplate will shapedinto cylindrical form while passing www!! the sets of rollers. e 'l The vertical spindles l of the various' outside rollers and the transverse-spindles 1 ot the Vilpper or inside rollers I may be supported by bearing brackets l secured toy a framework Lalhe outside rollers may'be driven from a main shaft Il'through'spur gearing I2,V a countershaft Il.y bevel gearing |74, transverse shafts il, worms il and worniwheels Il. l 'Ihe inside rollers l of sets A and Bvmay be positively driven as by being bevel geared as Vat izto the respective side rollers 3, but such insiderollers as well as those ofsets QC, D, Eand F may, Vif desired, be devoid of posirotate `merely by friction in'Figures 5'and 6 whichmay be assumed to illustrate'the-Eset'ofrollers. It will also be seen.

from these' two figures vthat the transverse shafts Ii'are supported by 'bearing`brackets attached Ato. the brackets l `before referred to. a

According toF'Agure 7, which illustrates the set of rollersfthe vtwo inside rollers l are canted or tilted upwardly .towardsfeach other.the shaft 1 having opposltely-inclined portions 'la for the respective rollers. 4

`The rrollers; of set Gv (see the left handpart of Flgure' andFlgure 9) -comprise outside rolle..

ers la and inside rollers lasimilar to those oi the preceding set but..as at this stage'the platel `is closely approaching the ydesired cylindrical form, the inside rollers are of comparatively small diameter to avoid them-fouling the upper parts of the curved plate. For similar reasons. the inside rollers are mounted upona comparatively short `shaft 22:.fsupported by a hanger 2l depending from an overhead frame member 2l;-

The rollers of set H (i. e. thefinal set asseen in the rightv hand part of Figure 8 and in Figure 10). comprise two laterally-spaced outside rollers 3b having concave peripheries `oi substantially'.

semi-circular proiile, the upper and'lower rims 3c of -the two rollers' contacting with, orbeing in close proximity to, eachother in alignment withk 'the longitudinal centre line of the apparatus, thus defining a substantially circular passage or orince' 2l (Figure 12) conforming to the external contour of the pipe to be formed. The co-operating inside rollers 6b are'located within the confines of this passage Vor orifice and are of relatively small diameter and may be canted or tilted upwardly away from each other as seen in Figures 1'0 and 12. These rollers may be supported by an extension 23a of the hanger 23 which supports the rollers 6a ofset G. The hanger and frame may be reinforced by stays 25 (Figure 8).

The aforesaid orifice or passage furnished by the rollers 3b of set H is preferably not trulylcircular but of slightly greater diameter measured horizontally than vertically so that the plate 2 in passing between the rollers is slightly elliptical. As soon as the plate passes the two rollers, however, the resilience of the plate causes it to assume a substantially truly cylindrical form as indicated in Figure 12.

The vertical spindles 4a of the outside rollers 20 da, 3b may be supported by bearing brackets 8a secured to the framework 3 and driving connections similar to those referred to in connection with the preceding set of rollers may extend from. countershaft I3 to worm wheels l1 associated with the outside rollers.

vIt will be evident from the foregoing that, as

I end to a tubular form at the other end with the jos side edges curved upwardly to a progressively greater extent from the flat to the tubular end. This procedure and formation which results in the central portion of the plate remaining fiat until the plate assumes cylindrical form ensures that the pipe will be practically perfectly straight from end to end.

In order to prevent any possibility of the central flat portion of the plate sagging due to roller pressure duringv the bending process,v a bearer IIJ may extend lengthwise beneath the centre portion of the plate so as to contact with the under surface thereof as in Figures 5, 7, 9 and 10.

The longitudinal meeting edges of the plate 2 may be progressively welded together soon after they emerge from the orifice or passage 26 provided by rollers 3b. In order to assist effective welding, a backing member 26 may be arranged to bear upwardly against the internal surface of the now cylindrical plate in vertical alignment with the welding electrode 21. The backing member, which may be of copper in order to exercise a desirable chilling effect upon the line of weld, may have a depending stem 28 engaged at its lower end by a spring 29 anchored to an upper bar 30 attached at its front end to the rear of the hanger 23. A lower bar 3| may also be attached at'its front end to the hanger and secured at its rear end to the upper bar by straps 32. 'I'he backing member may be provided at its front with an anti-wearing piece such as a steel nose 33.

Provision may be made for cooling the backing member by suitable fluid. For example, the backing member and a separable base 34- therefor may be provided in their contiguous faces with grooves 35, 36 defining a passage 31 for'water or the like which may be circulated through the passagefrom a supply pipe 38 to av discharge pipe 39. A gasket may extend between the backing member and its base to prevent leakage of'fiuid from the passage.

In the case of manufacturing comparatively small diameter pipes, say upto six or eight inches in diameter, there is a possibility that, owing to shrinkage or contraction taking place during the cooling of the welded joint, the resultant pipe may lose its desirable straightness and become slightly curved, in a longitudinal direction, the curvature beingv concave along the line of the weld. To counteract any such tendency, the bed of the machine may be roached or alternatively, the sets of rollers commencing from set B may be successively arranged at a slightly lower level than each preceding set of rollers, so I late or separate the final set of rollers H from the btherset of rollers so that the plate may be first shaped into partially cylindrical formby sets A to G, then removed and passed through the set H which may, with the appropriate welding plant, form la. separate unit.

'I o permit ofthe production of pipes of differ- 'ent diameters, the brackets 8, 8a supporting the spindles of rollers 3, 3a, 3b and 6, 6a,"6b may be adjustable in a lateral direction upon the frame 9. Alternatively, thebrackets may be mounted upon longitudinallyextending beams or frame ,members which may be swung or adjusted towards and from each other so that the lateral spacing of the rollers may bevaried to suit vthe diameter of the pipes .to be formed. The rollers may be readily removed from their spindles and replaced by -other rollers lhaving peripheries of the requisite contour.

Having now described my invention, what `I claim as new and desire to secure by Letters Patent is: r l

1. Apparatus for manufacturing pipes and like hollow bodies from flat metal plate; comprising sets of shaping rollers, between which the plate is caused to pass, arranged lat intervals in the direction of .travel ofthe plate, some of the rollers of eachset vbeing located at one side and the other rollers at the opposite side of the longitudinal centre lineof the plate, each succeeding set of rollers being disposed nearer to theflongitudinal centre line of the plate than the preceding set so that the plate is progressively bent from its longitudinal edges towards the centre thereof into tubular form, the final set of rollers -cmprising two outside rollers adapted to rotate about vertical axes and having peripheries ofv concave semi-circular profile defining'between them an orifice conforming substantially to the external circular form of the pipe to be produced, and two co-operating inside rollers disposed within said orifice or passage on opposite sides of the longitudinal center line of the plate and adapted to rotate about different axes which extend transversely relatively to the path of travel of the plate, the peripheries of the inside rollers being of convex curvature conforming to the internal curvature of the pipe to be formed.`

2. Apparatus according to claim 1; in which the diameter of the orifice or passage defined by said loutside rollers of the final set of rollers is slightly greater measured in one direction than in a direction at right angles thereto so that the plate may assume a slightly elliptical form in passing between said rollers and after emerging therefrom may automatically assume a substantially true circular form.

3. lApparatus for manufacturing pipes and like hollow bodies from at metal plate, comprising sets of shaping rollers between. which the plate is caused to pass, arrangedat intervals in the direction oftravel of the plate, some of the rollers of each setbeing located at one side and the other rollers at the opposite side of the longioenter line of theplate, each set of rollers 4comprising two lower or outside rollers adaptedY to rotate about vertical axes and having periph- Y veries'off. concave curvature conforming to the ei:-

ternaljcur'vatue of the pipe to be formed, and two' cooperating upper or inside rollers mounted yon oppositesides of the longitudinal centerline of the plate and adapted to rotate aboutdiiierent axes which -extend transversely relatively to the path of travel of therate and -having peripheries of convex curvature conforming to the internal. curvature of the pipe to be formed, each fsucceeding set of rollers being disposed nearer'to the longitudinal center line of the plate than the preceding yset so'that the' plate is progressively bent from its longitudinal edges towards the center thereof into tubular form.

4'. An apparatus for manufacturing pipes and like hollow bodies from fiat metal plate, compris- -finga plurality of spaced sets of shaping rollers arranged at intervals in the direction oftravel of the plate and through which the plate is progressively caused to pass. the first set of rollers through which-said plate is passed having pairs of rollers positioned to engage portions of the plate' adjacent the side'edges thereof and bend the edges toward each other to forma bend in y said portions'having a radius o! curvature equal to the radius of the pipe to be formed, whileleaving the central portion of the lplate ilat, each successive set of rollers through which the plate is passed having pairs of rollers positioned to engage ilat portions of the plate immediately adjacent the bentportions formed by the set of rollers from which the plate has just passed and bend the side edges oi.'- the plate closer'together 4to form in said last-mentioned ilat portions a bend adjacent to and continuous with the previously-formed bend and having the same radius of"cur vature, whereby the flat portions'of the plateon opposite sides ofthe longitudinal center line are progressively bent toward each other in arcuatetorm until the longitudinal side edges meet without bending the previously-bent portions, the nal set of rollers comprising two outside rollers adapted to rotate about vertical vaxes and having peripheries ofl concave semi-cir-V cular profile defining between them an orice conforming substantially to the external circular form of the pipe to be produced, and Aeach set vof rollers including two cooperating inside rollers mounted on opposite sides of the longitudinal center line' of a plate fed through the apparatus for rotation about axes which extend transversely relatively to the path of travel of the vplate within said oriilce and having peripheries conforming to the internal curvature of the pipe to be formed.

5. An apparatus forI manufacturing pipes like hollow bodies from ilatl metal plate, comprising a plurality of spaced sets of shaping rollers arranged at intervals in the direction of travel oi' the plate and through which the'plate is progressively caused to pass, the first set oi' rollers through which said plate is passed having pairs of rollers positioned 4to engage portionsfofthe vplate adjacent the side edges thereof and bend the edges toward each other to form a bend Vin saidportions having va.' radim of curvature equal to the radius of the pipe to be formed. while leavingA thecentral portion of the plate dat, each suecessive set of rollers through'which the plate is passed having pairs of'rollers positioned to engage yfiat portions of the plate,lmmedlatclyad-` jacent the bent portions formed by the set o! rollers fromwhich the plate has Just bend the side edgesof the plate closer together to form in said last-mentionedflat portions a bend'adjacent to and continuous with the previously formed bend and having the same radius of curvature, whereby the. iiat portions 'of the plate on opposite sides of the longitudinal center line are progressivelyfbent toward each other in arcuate form until the longitudinalsideodges meet without bending' the previously-bent por.

tions, eachv succeeding aet'ot rollers being arranged at a slightly lower level for imparting a downward Icurvature to 'the tube being formed to compensate iofr warpage due to shrinkage upon vwelding the side edges of the bentplate together kto complete the tube, the iinal-set of rollers comprising two outside. rollers adapted' to rotate labout vertical axes and'havlng peripheries of concave semi-circular pronle defining between them an orice conforming substantially to the external circular form of the pipe to be produced and each set of rollers including two cooperating inside rollers mounted on opposite sides ofthe longitudinal center line'of a plate fed through the apparatus for rotation about axes which extend transversely relatively to the path of travel oi the Vplate within said oriilce and having peripheries conforming to the internal curvature `of the pipe to be formed.

Y v 6. In a roller bending apparatus for producing 'pipes' and. like hollow bodies from hat metal plates, a' set of shaping rollers comprising outside rollers adapted to Vrotate about vertical axes and having peripheries of concave, approximately semi-circular, profile denning between them an Vorifice having a diameter y somewhat greatermeasured in one direction than in a direction lat a right angle thereto, and two cooperating` inside rollers mounted on opposite sides of the longitudinal center line of a plate fed through the apparatus for rotation about difl'erent axes which extend transversely relatively` to the path of travel of said plate within said orifice and having peripheries conforming to the internal curvature of the pipe to be formed. o l

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